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#1 2014-10-04 15:52:49

Terraformer
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From: Lancashire
Registered: 2007-08-27
Posts: 3,108
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Sewage treatment

Thermochemical treatment of sewage sludge.

It looks like pyrolysis is the way to go. Maybe we can tune it to optimise the production of hydrocarbons needed for plastics? If not, we can always find a use for hydrogen...


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#2 2014-10-05 07:48:03

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 16,181

Re: Sewage treatment

The term Alternative Fuels comes to mind such as BIOFUELS, INCLUDING BIOGASOLINE AND SOLAR BIODEISEL


THE%20BIOFUELS%20WATER,%20CARBON,%20OXYGEN,%20AND%20ENERGY%20CYCLES.JPG


solar%20appleseed%20biodiesel%20SMALL.JPG

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#3 2014-10-05 08:52:19

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,794
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Re: Sewage treatment

On Earth, many people think of "waste" as something that has to be disposed of. They just can't think in terms of recycling. In nature, every organism's waste is some other organism's food. We have to think that way. Sewage is extremely high in nitrogen and phosphorus fertilizers. Here in Winnipeg, the city sewage treatment facilities first use a tank as large as an Olympic swimming pool to with metal rakes at the surface to remove toilet paper. Then a settling tank. Then the sediment goes to digester tanks that use anaerobic bacteria to break down solid human waste (shit). The result from digesters is something called "night soil". It's used as fertilizer for fodder, sometimes called animal feed. Manure from farms, particularly hog farms, is used as fertilizer for food crops. But "night soil" is used to fertilize crops for animals. The reason is E. coli or other micro-organisms that could be in fertilizer; the danger of that getting on food. So human waste is used to fertilize crops that are fed to animals, and animal waste is used to fertilize crops for humans.

There have been efforts to process toilet waste so human waste could fertilize food crops directly.

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#4 2014-10-05 12:07:01

Void
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Registered: 2011-12-29
Posts: 3,011

Re: Sewage treatment

I hope I don't annoy you jumping on your threads all the time.

Anyway, if I had to try to solve the problem, I would have a 2nd floor overhang projecting from the shelter on stilts.

Under that I would have a set of three "Drums".  This projection would point towards a pole.  I am presuming the shelter would be in a temperate zone location.

The drums would hold full air pressure (We hope) along with the rest of the shelter.  Being in the shadow of the shelter, I expect the drums to persist at temperatures well below the freezing point of water.

Above each drum inside the shelter, a lid, and some method of a toilet seat.  For good measure, the seats should be capable of vacuum integrity.  Should a drum rupture, and the lid be closed, it should have high probability of holding air pressure against any vacuum appearing in a drum.

1) Drum 1 would be where you did your urination.  Your urine would freeze and so be stored, and to a small degree sterilized by ice crystals.

2) Drum 2 would be where you drop the big ones.  (Use a hoist if necessary). smile  A freezing process to partially sterilize and make quiet organic decomposition.  Reducing bad odors to a minimum.

3) Drum 3 would be between the two, and would be where you drop your "paper" waste.

At some point the drums are sufficiently filled to require a altered process.  I do not want anything requiring lifting dirty heavy things.  That could be messy and could cause back injuries, or if you use pipes for water based fluids, you are then getting into lots of complications, except during a relatively brief period when you may finally empty them.

So, you have to have at least one alternate set of such drums for use while you are dealing with the frozen wastes in the 1st set.

You put a thermally insulating wall around the 1st floor enclosure, attached to the stilts that hold up the 2nd floor.  You heat that enclosure by some means, thawing the contents of each drum.  (The lids are firmly closed).

For drum 1, I think that then you can extract Ammonia, which would result from the breakdown of urine.  Urine is typically not very infectious.  Secondary sterilization could be considered however, perhaps a UV light.  Or maybe you can think of something else.  After that you have to either have a tank on a wheeled cart to suck the residual fluids into, or a established pipeline.  You dump the residual fluids to whatever thing you want to.  Perhaps you use it in agriculture, or you squirt it outside.

For Drum 2, I would go ahead and try to establish a digestive process that consumes the human organic matter in the waste paper, feces, mucus, etc, but largely leaves the cellulose alone.  This could be without Oxygen, producing some Methane, or with Oxygen if that is more suitable.  After it is processed, you vacuum out the water content as vapor, and dispose of it or condense it for watering a garden.  Perhaps during the drying process a low level of heat would be used to help sterilize it.  When the left overs are
dry they will be less obnoxious to the hab environment and can be taken out for further recycling.  Perhaps if necessary back to paper, or my preference would be to make some kind of particle board out of it.

For Drum 3, your standard process of digestion without Oxygen, producing Methane.  When that is done, again drawing out the vapors of water, and applying a low level of sustained dry heat.  At that point the digested dried residual will be less obnoxious, and again someone would have to basically scoop it out, and if it is sterile enough, it goes to a garden.  Alternately if they want to they can try to pump it out as a fluid, but spills would be obnoxious, and cleanup of a spill would be a burden, especially on paper products.

For paper, I think most of us who have been in the woods and have an emergency, have used leafs on some occasion.  It does not work that well.  However, if a plant of suitable character could be found, and the leafs treated to remove the non-cellulose part of the leafs, perhaps that could work.  They would be producing Oxygen, paper product (Sort of), and ultimately that would be converted into some type of particle board like product (Perhaps).

Last edited by Void (2014-10-05 12:11:00)


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#5 2014-10-05 17:23:34

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,794
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Re: Sewage treatment

One thing most people don't realize: urine is sterile. At least when it first comes out of your body. After all, your kidneys filter it out of your blood. Of course any organism in the toilet or where ever you go will start working on it right away. The yellow stinky stuff is urea, which is two molecules of ammonia bonded with a carbonyl group. Chemical forumula CO(NH2)2. There is an enzyme called urease that breaks down urea, adding one water molecule.
CO(NH2)2 + H2O -> 2 NH3 + CO2

Last spring my toilet needed repair. I noticed urine left a couple hours changed to cloudy and the smell changed. I smelled like an outhouse. That tells me something was growing in it. So the particularly foul smell wasn't human urine itself, it was the microorganism(s).

Human urine isn't just urea, water and salt. There are other things our kidneys filter out of our blood. It's mostly small molecules, because they get through the filter that is our kidneys. There's sugar, protein, etc. No wonder microorganisms love it.

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#6 2014-10-05 17:34:47

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,794
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Re: Sewage treatment

A permanent Mars settlement will have an issue with toilet paper. There aren't any trees. Do we need a large greenhouse just to grow trees for TP? A simpler solution is a washlet. That's a special seat on a normal toilet. The seat is a bidet. So you wash your bottom after doing your business. Not in a separate bidet, but just the same toilet. More expensive models of washlet have an electric warmer for the water, and a warm air blower that works like a hand dryer in a public washroom. So you clean and dry your bottom before getting off the toilet. And use nothing but water, air, and electricity.

The washlet was invented in Tokyo, where most homes aren't connected to a city sewer. Each home has a septic tank, which gets clogged quickly by TP. Urban septic tanks are drained by a "honey wagon" (English term), a truck with a tank to collect sewage and a hose to suck it up. Using TP means the honey wagon has to come several times more often. That service charges for each pickup. So the washlet is just practical for Tokyo. It would be practical for Mars as well.

However, that raises another point. The "BioMars" group studied a grey water sewage treatment system. Terry Kok led an effort called the Green CELSS Taskforce; his effort was based on a composting toilet. So water, or no water? Both groups endeavoured to produce fertilizer for food crops.

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#7 2014-10-05 19:13:53

louis
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From: UK
Registered: 2008-03-24
Posts: 4,924

Re: Sewage treatment

RobertDyck wrote:

A permanent Mars settlement will have an issue with toilet paper. There aren't any trees. Do we need a large greenhouse just to grow trees for TP? A simpler solution is a washlet. That's a special seat on a normal toilet. The seat is a bidet. So you wash your bottom after doing your business. Not in a separate bidet, but just the same toilet. More expensive models of washlet have an electric warmer for the water, and a warm air blower that works like a hand dryer in a public washroom. So you clean and dry your bottom before getting off the toilet. And use nothing but water, air, and electricity.

The washlet was invented in Tokyo, where most homes aren't connected to a city sewer. Each home has a septic tank, which gets clogged quickly by TP. Urban septic tanks are drained by a "honey wagon" (English term), a truck with a tank to collect sewage and a hose to suck it up. Using TP means the honey wagon has to come several times more often. That service charges for each pickup. So the washlet is just practical for Tokyo. It would be practical for Mars as well.

However, that raises another point. The "BioMars" group studied a grey water sewage treatment system. Terry Kok led an effort called the Green CELSS Taskforce; his effort was based on a composting toilet. So water, or no water? Both groups endeavoured to produce fertilizer for food crops.

Perhaps we can create a hi-tech equivalent of the Roman sponge stick.


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#8 2014-10-05 20:56:28

Void
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Registered: 2011-12-29
Posts: 3,011

Re: Sewage treatment

The wet process you suggested with water cleaning is just as good to consider as any other, the same for the sponge stick.

I rather don't like that one, the sponge stick, but with updating, perhaps it could be helpful.  A personal one for each member I hope.  And some method to sterilize it?

A water budget is a factor.  Mars offers more chances on that than other reachable places in space.  I guess each technology will perhaps advance over time, and choices will be made on what is prudent for the situation that may exist in a settlement.

As for devoting a greenhouse to growing toilet paper, I will counter argue (If we don't discuss things, this site will get pretty dead).  But let me know if you are tired of me an my antics, and I will either try to modify my ways, of just go.  (Without bitterness).

So my argument would continue as follows.

If you can build greenhouses and have enough materials and time and energy to build more than the minimum needed for crops, why not do so?

I have not seen a reasonable proposal for a substitute for wood, except perhaps bamboo, which is a wonderful plan if you can do it.  Again it would be nice to be able to build lots of greenhouse space, if economics permitted it.  I would hope for a rich population  If so, what would they want?  If poor, then choices have to be made.

So, I don't have an ideal plant in mind, but I will propose rhubarb.  It has some vitamins but is not a particularly high gain food.  As I have said I am using it for a proxy for a hoped for more useful plant.  But I need to start with something.

So, you are growing rhubarb, which is fairly rugged.  If you could remove the non cellulose content, perhaps the leaves would be useful for a paper towel substitute.  People will have to blow their noses at least and they would need to wipe things up.  What I propose is rather wimpy for the task but it is not worthy of having a pillow put over it's head and suffocated just yet.  I hope for something much better.

I know that cloth items that would be washed are also proposed for those tasks.  But then there is a washing cost.  But maybe it is a good way.

Anyway, if your intention was to grow a plant that could produce a wood substitute product, then you have that, and you also have a pseudo paper product.  You have generated Oxygen, and parts of the plant are food.

But I want to be specific that I am not wild about rhubarb as the plant, I just wanted a symbolic place marker for the item that I hope exists.

I might also suggest that if you could harvest the chloroplasts from the "Rhubarb", and so some of the things with that that have been proposed for peas, then you got something else as well.  Was that you RobertDyck?  I am not all that sharp about assigning credit where it belongs.

I might finally say that if a Roman Sponge Stick is OK (And I think it could be), then making a wood substitute, perhaps a low grade pseudo particle board from pseudo "Paper" that was used for body and house cleaning is not necessarily out of the question.  I do believe a reasonable sterilization could be accomplished.

But I am not ever going to Mars, so I guess all of this will be a Martians choice in the end.


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#9 2014-10-05 22:30:47

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,794
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Re: Sewage treatment

I heard that ancient Rome soaked their sponge in vinegar. That would help sterilize it, but I don't think I would want to wipe my ass with vinegar.

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#10 2014-10-05 22:48:12

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,794
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Re: Sewage treatment

Yea, I was the person who proposed harvesting chloroplasts from the leaves of pea plants. The idea was to use photosynthesis to recycle CO2 + water into O2 + carbohydrate. So it would use sunlight reflected with a mirror through a window as primary energy source to generate oxygen, instead of electricity collected via photovoltaic panel. It also produces carbohydrate as a by-product, instead of toxic gasses that have to be dumped in space. Which carbohydrate depends on which plant you get the chloroplasts from. Peas produce pea starch. The issue with this is how to extract isolated chloroplasts from leaves. The documents I got from a university biochemistry professor said peas are the easiest. Easy is good. A few other plants are listed. Rhubarb isn't listed, so I don't know if you can isolate chloroplasts from rhubarb without destroying the chloroplasts you want.

If you use a grey water sewage treatment system, that water will end up in soil of a greenhouse. Then plants filter that water through leaves, producing humidity in the greenhouse. That humidity will condense on cold windows of the greenhouse, dripping/running down to a collection trough at the bottom. That water, filtered through plants, is far better tasting than the best filtration system that NASA ever developed. So as long as you can safely process sewage into fertilizer for food crops, the water is contained within a closed system. And if you use a grey water system, then a washlet is practical.

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#11 2014-10-05 22:59:58

Void
Member
Registered: 2011-12-29
Posts: 3,011

Re: Sewage treatment

Peas on the World of Mars, and goodnight.


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#12 2014-10-07 07:19:40

Terraformer
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From: Lancashire
Registered: 2007-08-27
Posts: 3,108
Website

Re: Sewage treatment

Hmmm. Now I'm thinking of having four separate waste streams - one for urine, another for excrement, a third for paper, and a fourth for the disposal of other wastes (tampons, condoms, goldfish...). Urine can be treated fairly easily it seems, and the bulk of the paper stream is going to be toilet paper with a bit of excrement, so perhaps it can be incinerated? That should make the excrement stream much easier to process. I don't know what you do with the goldfish.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#13 2014-10-07 08:29:44

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,794
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Re: Sewage treatment

Terraformer wrote:

I don't know what you do with the goldfish.

Cat food?
hd-cats-wallpaper-with-a-cat-trying-to-catch-a-goldfish-wallpapers-660x330.jpg
But seriously, we wouldn't have pets on Mars. Not for a while. Besides, dead goldfish could decay along with solid human waste to become fertilizer.

But again, with a grey water system, just don't use TP. That eliminates the need for a large greenhouse for trees. The washlet is simpler. And no need to separate waste streams. They did try to build such a system at MDRS, but had difficulty. In the end they removed the sewage processing system, and replaced the greenhouse. Not sure of their current status. Website here: GreenHab
uc?id=0BznHcN6hsqG2SVd2V0t1bE1oS28

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#14 2014-10-07 11:27:06

Terraformer
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From: Lancashire
Registered: 2007-08-27
Posts: 3,108
Website

Re: Sewage treatment

Ah, by "goldfish" I meant "non-standard sewage waste" such as condoms and tampons (see first mention of goldfish in my post above...). Just make sure people put them in a separate bin?


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#15 2016-12-29 10:15:03

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 16,181

Re: Sewage treatment

Waste not want not as we spent the funds to bring it there we need to make sure that we have a plan for how to recycle it.
This as the posts which have been made for soils are a builder product short term and long term as a fuel source.

SpaceNut wrote:

Yes turning poop, sun, algea into fuel and fertilizer we have talked about for reclaiming processes.

Sun, sewage and algae: a recipe for success?

If all goes to plan over the next five years, the plant will produce about three tonnes of algae a day from 10 hectares of ponds, enough to run about 200 vehicles. First, much of the organic matter will be anaerobically digested to produce methane, another fuel source. This is already done on in some tropical countries and for special waste waters, such as that from breweries. The reason for the pre-treatment is so the algae don't have to battle it out with bacteria for the organics. Instead, the carbon dioxide produced alongside the methane is pumped back into the waste water, to feed the algae. A key advantage of the proposal is that the waster water is already full of the nutrients - nitrogen and phosphorus - that the algae need to grow.

Is "Peecycling" the Next Wave in Sustainable Living? Human waste can be converted into valuable fertilizer, if people can get past the "ick" factor.

human urine makes up less than one percent of the domestic wastewater treated at a facility such as Blue Plains, but contains 80 percent of the nitrogen and 55 percent of the phosphorous. To sanitize urine before application, it is either stored for 30 days in a sealed tank in a room-temperature greenhouse (background) or heated for 30 minutes in a solar pasteurizer (foreground).

News: Algae Farming Technology Yields Renewable Fuel, Uses Waste as Fertilizer

Algae Basics - Benefits of Algae which talks about 10 reasons why algae are a promising new source of fuel and other products:

6 Ways to Convert Poop Into Electricity

Lake Matthew Team - Cole wrote:

Known Unknowns, Etc.

SpaceNut wrote:

Another topic suggestion area for soil type and conditioning for agriculture:

Soil Manufacture on Mars
Sewage treatment
Building Soil with Salt Marshes
Building soil
Mars regolith analog

There are some very creative ideas in those threads.  Focusing on soil, I find that many of the creative ideas for soil manufacture seem to introduce more unknowns than they remove.  For example, the idea of blending waste streams into the soil could introduce unpredictable fluctuations in toxins, microbes, pH and nutrient loads.  On Earth, soil microbes are diverse and abundant, and their metabolisms help the soil manage fluctuations.  But on Mars, most of the beneficial soil microbes would be absent unless explicitly cultivated.  Perhaps fluctuations could be managed by the greenhouse crew, but it would seem to be a worrisome job.  It's just more unknowns.

Hydroponics removes unknowns by simplifying the soil down to an inert substrate, such as pH-neutral rinsed sand.  In a greenhouse with ISRU fertilizer, sterile nutrients are added in a controlled manner, again removing unknowns.  A microbiome isn't required and can be suppressed, to remove even more unknowns.  For example, a plasma nitrate plant makes hydrogen peroxide as a byproduct.  That hydrogen peroxide is added to the liquid nitrate fertilizer to kill off soil pathogens without harming the plants.   (Conceivably this treatment could remove a further unknown:  hypothetical Mars pathogens.  Microbes evolved under anoxic conditions really don't like sudden peroxide oxygen baths.)

To my mind the removal of unknowns is a main reason to aim for a hydroponic greenhouse, one having no more organic matter in the substrate than may be necessary for water retention.  A little cellulose could be adequate.

But am I missing something?  Is there good reason to convert sand substrate into a soil that's rich in organics, microbes, worms, etc., in this unique circumstance?

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#16 2016-12-29 16:15:46

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,719

Re: Sewage treatment

Many years ago, I remember being able to buy a fertilizer at the hardware, ranch supply, and feed stores called "Milorganite." It was the dried and sterilized poop from the city of Milwaukee. In the waste treatment plants of most large cities, there are several steps to processing, one of which is centrifugation for removal of solids. The waste water is subsequently treated either by aeration or addition of various chemical agents. If toilet waste can be segregated such that tampons and condoms are trapped before entering the centrifuge, this new "Marsite" fertilizer can be used in agriculture.

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#17 2016-12-29 17:17:58

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,653
Website

Re: Sewage treatment

People have been fertilizing their food crops with their own sewage for millennia in the far east.  It's part of why parts of Korea,  China,  Japan,  and Indochina smell so bad.  Nothing new there.

But,  you WANT the biological critters in the waste!  They're an integral part of the ecosystem/ecology you are trying to build!  Do not treat it,  do not sterilize it.  Just filter out the tampons,  etc. Which should never go down the toilet in the first place.  Anybody with a septic tank knows THAT.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#18 2016-12-29 18:04:29

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 16,181

Re: Sewage treatment

We can look to the ISS for the levels of bacteria that we will have that will either benefit or harm us for if we do use poop for the gardening enhancing of its soils initially. Also as the other post in this topic show we can do more than just spread it on the fields.....

ISS Links
International Space Station Internal Environments (ISS Internal Environments) - 11.22.16

Microbial Creatures in Space

Spaceflight Alters Bacterial Social Networks

Space Microbiology

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